Tropical fruit trees such as mangos and avocados are grafted in tropical locations through seeds. In the U.S. where cultivators are more likely to grow different varieties in close proximity, seeds are not considered a reliable means of cultivation. Instead techniques such as budding, cuttings and grafting are employed. In addition, seeds are still used for producing the rootstock to which the branches are grafted.
Verify the health of the rootstock by checking for bark degeneration and pests. If large sections of the bark are missing, or the tree has not leaves or is rotting, do not use it for rootstock.
Select healthy budwood roughly the same diameter as the rootstock. Cut the budwood to be roughly four to six inches long.
Use the sharpened grafting knife to slice the top of the rootstock and the bottom of the budwood diagonally. The cut should be roughly two inches long and should be made with a clean cut. Do not saw the wood, as it will damage the cambiums.
Press the two pieces together, matching up the cambium layers as closely as possible. The cambium layers are the green layers of the plants just below the bark. In order for a graft to take, at least 60% of the two plant's cambial layers must line up.
Wrap the grafted branches tightly in grafting tape to promote a strong bond.
Care for the tree as usual (water and fertilize) and remove the grafting tape after eight weeks, or once new growth forms on the budwood. If the new growth appears to be forming slower than growth normally would for that variety of tree, then remove any limbs that are lower than the grafting point. This action will force more nutrients to the graft site.